Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailBacterial diversity of field-caught mosquitoes from different regions of Belgium and potential impact on virus transmission
Raharimalala, Fara Nantenaina ULg; Boukraa, Slimane ULg; Bawin, Thomas ULg et al

Poster (2013, October 02)

Several vectors disease presented a resistance to various pesticides currently used. Endosymbiotic bacteria was an alternative solution found because of their probably interactive effects with their host ... [more ▼]

Several vectors disease presented a resistance to various pesticides currently used. Endosymbiotic bacteria was an alternative solution found because of their probably interactive effects with their host. According to the introduction risks of these virus and disease dispersion, we propose to investigate the bacterial endosymbiont role in Culicidae in Belgium. Among the 30 species of mosquitoes identified in this country, about ten are considered as potential vectors of arboviruses. In this study, eleven species of Culicidae belonging to five genera (Culex pipiens s.l., Cx. torrentium, Cx. hortensis, Anopheles claviger, An. maculipennis s.l., An. plumbeus, Culiseta annulata, Ochlerotatus geniculatus, Oc. dorsalis, Aedes albopictus and Coquillettidia richiardii) mosquitoes fields from eight sites of Belgium were used for the screening of the presence of six genera endosymbiotic bacteria (Wolbachia sp, Commamonas sp, Delftia sp, Pseudomonas sp, Acinetobacter sp and Asaia sp) according their possible impact in mosquito biology. PCR was done for the screening of endosymbiotic bacteria mosquitoes studied. A total of 176 individuals (144 larvae and 32 adults) were used. Our results allowed us to confirm the absence of Wolbachia in An. clavigere, An. maculipennis s.l and Cx. torentium. Acinetobacter was found in every species. Current advances in understanding the mosquito–microbiota relationships may have a great impact in a better understanding of some traits of mosquito biology and in the development of innovative mosquito-borne disease-control strategies aimed to reduce mosquito vectorial capacity and/or inhibiting pathogen transmission. [less ▲]

Detailed reference viewed: 54 (15 ULg)
Full Text
Peer Reviewed
See detailBacterial diversity of field-caught mosquitoes, Aedes albopictus and Aedes aegypti, from different geographic regions of Madagascar.
Zouache, Karima; Raharimalala, Fara Nantenaina ULg; Raquin, Vincent et al

in FEMS Microbiology Ecology (2011)

Symbiotic bacteria are known to play important roles in the biology of insects, but the current knowledge of bacterial communities associated with mosquitoes is very limited and consequently their ... [more ▼]

Symbiotic bacteria are known to play important roles in the biology of insects, but the current knowledge of bacterial communities associated with mosquitoes is very limited and consequently their contribution to host behaviors is mostly unknown. In this study, we explored the composition and diversity of mosquito-associated bacteria in relation with mosquitoes’ habitats. Wild Aedes albopictus and Aedes aegypti were collected in three different geographic regions of Madagascar. Culturing methods and denaturing gradient gel electrophoresis (DGGE) and sequencing of the rrs amplicons revealed that Proteobacteria and Firmicutes were the major phyla. Isolated bacterial genera were dominated by Bacillus, followed by Acinetobacter, Agrobacterium and Enterobacter. Common DGGE bands belonged to Acinetobacter, Asaia, Delftia, Pseudomonas, Enterobacteriaceae and an uncultured Gammaproteobacterium. Double infection by maternally inherited Wolbachia pipientis prevailed in 98% of males (n = 272) and 99% of females (n = 413); few individuals were found to be monoinfected withWolbachia wAlbB strain. Bacterial diversity (Shannon–Weaver and Simpson indices) differed significantly per habitat whereas evenness (Pielou index) was similar. Overall, the bacterial composition and diversity were influenced both by the sex of individuals and by the environment inhabited by the mosquitoes; the latter might be related to both the vegetation and the animal host populations that Aedes used as food sources. [less ▲]

Detailed reference viewed: 2 (0 ULg)
Peer Reviewed
See detailBacterial fixation on feed particles and digestion of structural carbohydrates in the rumen.
Teller, E.; Vanbelle, M.; Beckers, Yves ULg et al

in Mededelingen van de Faculteit Landbouwwetenschappen (Rijksuniversiteit te Gent) (1989), 54(4a), 1377-1386

Detailed reference viewed: 30 (3 ULg)
Full Text
Peer Reviewed
See detailBacterial Intestinal Flora Associated with Enterotoxaemia in Belgian Blue Calves
Manteca, Christophe; Daube, Georges ULg; Pirson, Vincianne et al

in Veterinary Microbiology (2001), 81(1), 1-12

The enterotoxaemia syndrome in Belgian Blue calves is characterised by a high case fatality rate, sudden death, lesions of haemorrhagic enteritis of the small intestine and, quite often an absence of ... [more ▼]

The enterotoxaemia syndrome in Belgian Blue calves is characterised by a high case fatality rate, sudden death, lesions of haemorrhagic enteritis of the small intestine and, quite often an absence of other clinical signs but its cause has not been yet identified. As a first step in this identification, the aerobic and anaerobic intestinal flora of a population of 78 calves, originating from farms located in southern Belgium and that died in circumstances defined as "calf enterotoxaemia" (study population) and of 64 calves that died in other circumstances (control population) were studied qualitatively and quantitatively. The colonies were identified after subcultures with appropriate API sugar sets. Anaerobically Clostridium perfringens was isolated in higher numbers (mean values of 10(7)-10(7.5) colony forming units (CFU) versus 10(4)-10(5) CFU per ml of intestinal content) and from more animals (79 versus 19%) in the study population than in the control population, although individual results from both populations could overlap. Other clostridial species, i.e. mainly urease-negative C. sordellii and C. bifermentans, were isolated in high numbers (>10(6) CFU per ml of intestinal content) from a few animals in the study population only. All but one of the 705 C. perfringens isolates from both populations belonged to the A toxin type and none of the urease-negative C. sordellii was toxigenic. Gram-negative anaerobes were not isolated in high numbers from any of the samples. Aerobically beta-haemolytic E. coli were significantly more frequent among the study population, but were isolated from only 25% of the animals. Salmonella Typhimurium was isolated from only two animals in the study population. Less than 1% of the E. coli isolated were verotoxigenic and one-third were necrotoxigenic. At this stage only non-enterotoxigenic type A C. perfringens are thus statistically associated with the enterotoxaemia syndrome in Belgian Blue calves and fulfil the first of the Koch's postulates. [less ▲]

Detailed reference viewed: 98 (2 ULg)
Full Text
Peer Reviewed
See detailBacterial leaching of complex sulphides from mine tailings altered by acid drainage
Kitobo, Willy; Gaydardzhiev, Stoyan ULg; Frenay, Jean ULg et al

in Dominic, Esteban (Ed.) Bacterial leaching of complex sulphides from mine tailings altered by acid drainage (2009, May)

An experimental study aimed at re-flotation of laid down tailings from Kipushi (DRC) to bring sulphide concentrate suitable for further processing by hydrometallurgical means has been realized. The ... [more ▼]

An experimental study aimed at re-flotation of laid down tailings from Kipushi (DRC) to bring sulphide concentrate suitable for further processing by hydrometallurgical means has been realized. The results from a bioleaching route chosen to accomplish the later task by use of moderate thermophilic and mesophilic microorganisms are reported. It has been found that due to the complexity of the treated material, the leaching pattern of the two principal metals of interest, copper and zinc vary. Whilst the copper bearing minerals have been leached relatively fast by direct mechanism, the leaching kinetics for the zinc minerals has been moderate involving predominantly an indirect mechanism. The effects of pH and temperature variations and ferrous ions addition upon the extent of copper and zinc dissolution have been examined. The presence of ferrous ions has been found beneficial for the leaching of sphalerite, however the concomitant formation of jarosite precipitates has led to copper leaching hindrance. Similarly, the rapid zinc solubilisation has been counterbalanced by decrease in rate of copper dissolution. [less ▲]

Detailed reference viewed: 293 (35 ULg)
Full Text
Peer Reviewed
See detailBacterial mastitis in the Azawak zebu breed at the Sahelian experimental station in Toukounous (Niger) : Identification and typing of Staphylococcus aureus
Issa, Ibrahim Abdoulkarim; Bada-Alambedji, Rianatou; Duprez, Jean-Noël ULg et al

in International Research Journal of Microbiology (2013), 4

Detailed reference viewed: 16 (6 ULg)
Full Text
Peer Reviewed
See detailBacterial mastitis in the Azawak zebu breed at the Sahelian experimental station in Toukounous (Niger): Identification and typing of Staphylococcus aureus
Issa Ibrahim, Abdoulkarim; Bada-Alambedji, Rlanatou; Duprez, Jean-Noel et al

in International Research Journal of Microbiology [=IRJM] (2013), 4(7), 168-178

Detailed reference viewed: 33 (14 ULg)
Full Text
Peer Reviewed
See detailBacterial peptidoglycan (murein) hydrolases.
Vollmer, Waldemar; Joris, Bernard ULg; Charlier, Paulette ULg et al

in FEMS Microbiology Reviews (2008), 32(2), 259-86

Most bacteria have multiple peptidoglycan hydrolases capable of cleaving covalent bonds in peptidoglycan sacculi or its fragments. An overview of the different classes of peptidoglycan hydrolases and ... [more ▼]

Most bacteria have multiple peptidoglycan hydrolases capable of cleaving covalent bonds in peptidoglycan sacculi or its fragments. An overview of the different classes of peptidoglycan hydrolases and their cleavage sites is provided. The physiological functions of these enzymes include the regulation of cell wall growth, the turnover of peptidoglycan during growth, the separation of daughter cells during cell division and autolysis. Specialized hydrolases enlarge the pores in the peptidoglycan for the assembly of large trans-envelope complexes (pili, flagella, secretion systems), or they specifically cleave peptidoglycan during sporulation or spore germination. Moreover, peptidoglycan hydrolases are involved in lysis phenomena such as fratricide or developmental lysis occurring in bacterial populations. We will also review the current view on the regulation of autolysins and on the role of cytoplasm hydrolases in peptidoglycan recycling and induction of beta-lactamase. [less ▲]

Detailed reference viewed: 48 (2 ULg)
Full Text
See detailBacterial Peptidoglycans in Relation to the Membrane and the Mechanism of Action of Penicillin
Ghuysen, Jean-Marie ULg; Leyh-Bouille, Mélina; Perkins, Harold-R. et al

in Vanek, Z.; Hostalek, Z.; Cudlin, J. (Eds.) Genetics of industrial microorganisms. Bacteria (1973)

Detailed reference viewed: 12 (0 ULg)
Peer Reviewed
See detailBacterial production and purification of recombinant human prolactin
Paris, N.; Rentier-Delrue, Françoise ULg; Defontaine, A. et al

in Biotechnology & Applied Biochemistry (1990), 12(4), 436-49

Escherichia coli cells transformed with a recombinant plasmid (pT7L) containing the coding sequence of human prolactin (hPrl) expressed a new protein. This protein, comigrating with human Prl on sodium ... [more ▼]

Escherichia coli cells transformed with a recombinant plasmid (pT7L) containing the coding sequence of human prolactin (hPrl) expressed a new protein. This protein, comigrating with human Prl on sodium dodecyl sulfate (SDS)-polyacrylamide gels, represented 50% of the total bacterial extract. Immunoprecipitation of [35S]methionine-labeled bacterial lysate with a rabbit antiserum to hPrl followed by SDS-polyacrylamide gel electrophoresis (PAGE) analysis showed that the major component had a Mr identical to that of standard hPrl. The majority of the recombinant hPrl (r-hPrl) accumulated in inclusion bodies. Analysis of these inclusion bodies by SDS-PAGE under nonreducing conditions showed that they are composed mostly of fully reduced monomers. Solubilization of the inclusion bodies and protein denaturation were performed in 8 M urea. Refolding during the renaturation procedure was confirmed by SDS-PAGE under nonreducing conditions. r-hPrl was further purified by gel permeation chromatography on a fast protein liquid chromatography column. More than 95% of the molecules were recovered as oxidized monomeric forms. The refolded molecule was tested for its bioactivity in the Nb2 lymphoma mitogenic assay. The dose-response curves obtained with either r-hPrl or pituitary-derived hPrl showed a complete parallelism. Furthermore, Nb2 cell proliferation was completely blocked by addition of hPrl antiserum to both preparations. Recombinant hPrl is identical to natural hPrl except for an additional methionine group at the amino terminal end. [less ▲]

Detailed reference viewed: 61 (7 ULg)
Peer Reviewed
See detailBacterial protein synthesis in the pig's large intestine varies according to the fermented non-starch polysaccharides.
Bindelle, Jérôme ULg; Leterme, Pascal; Destain, Jean-Pierre ULg et al

in Journal of Animal Science (2007), 85(Suppl. 2), 114-115

Detailed reference viewed: 25 (1 ULg)
Full Text
Peer Reviewed
See detailBacterial symbionts and mineral deposits in the branchial chamber of the hydrothermal vent shrimp Rimicaris exoculata: relationship to moult cycle
Corbari, Laure; Zbinden, Magali; Cambon-Bonavita, Marie-Anne et al

in Aquatic Biology (2008), 1

Detailed reference viewed: 14 (3 ULg)
Peer Reviewed
See detailBacterial wall peptidoglycan, DD-peptidases and beta-lactam antibiotics
Ghuysen, Jean-Marie ULg; Frère, Jean-Marie ULg; Leyh-Bouille, Mélina et al

in Scandinavian Journal of Infectious Diseases (1984), 42

Wall peptidoglycan expansion in bacteria rests upon a cytoplasmic D-Ala: D-Ala ligase (ADP) which catalyses synthesis of a D-Ala-D-Ala dipeptide (with accompanying hydrolysis of one molecule of ATP) and a ... [more ▼]

Wall peptidoglycan expansion in bacteria rests upon a cytoplasmic D-Ala: D-Ala ligase (ADP) which catalyses synthesis of a D-Ala-D-Ala dipeptide (with accompanying hydrolysis of one molecule of ATP) and a set of DD-peptidases which utilize this D-Ala-D-Ala dipeptide--once it has been translocated at the outer face of the plasma membrane as the C-terminal portion of a disaccharide peptide unit--as carbonyl donor for transpeptidation and carboxypeptidation reactions (without additional energy expenditure). Four DD-peptidases have been selected which differ from each other with respect to the effects that amino compounds exert on the fate and rate of consumption of a D-Ala-D-Ala terminated amide carbonyl donor analogue. They serve as models to understand the different mechanisms by which the DD-peptidases perform catalysis and show widely varying responses to the action of beta-lactams, from extreme sensitivity to very high resistance. [less ▲]

Detailed reference viewed: 60 (14 ULg)
Full Text
See detailBacterial Wall Peptidoglycans; Mecanism of Action of Penicillin
Ghuysen, Jean-Marie ULg; Leyh-Bouille, Mélina

in Genetics of Industrial Microorganisms : abstact book (1970)

Detailed reference viewed: 8 (0 ULg)
Full Text
Peer Reviewed
See detailBactericidal activity against Pseudomonas aeruginosa is acquired by cultured human monocyte-derived macrophages after uptake of myeloperoxidase.
Mathy-Hartert, M.; Deby, Ginette ULg; Melin, Pierrette ULg et al

in Experientia (1996), 52(2), 167-74

Myeloperoxidase (MPO) is an enzyme located within polymorphonuclear neutrophils capable of producing cytotoxic oxidant species that are particularly active against bacteria with polysaccharide capsules ... [more ▼]

Myeloperoxidase (MPO) is an enzyme located within polymorphonuclear neutrophils capable of producing cytotoxic oxidant species that are particularly active against bacteria with polysaccharide capsules. Pseudomonas aeruginosa (10(6) bacteria per 1ml) are killed within 1 h in vitro by a MPO/H2O2/C1- system (48mU=132ng of MPO). The question arose as to whether human macrophages would acquire cytotoxic activity when loaded with this enzyme. Monocytes were therefore isolated from human blood and cultured for up to ten days to induce maturation to macrophages. These cells lost endogenous MPO within five days while H2O2 production in response to stimulation by phorbol myristate acetate (10(-6)M) decreased to 23% within ten days. On the other hand, their capacity to take up exogenous MPO increased fourfold from day three to day ten. Human macrophages cultured from eight days (when both H2O2 production and MPO uptake were sufficient) were therefore used to study the effects of MPO uptake on cytocidal activity against Pseudomonas aeruginosa. After a 1 h MPO loading period, macrophages (5X10(5) cells per ml) were incubated in the presence of bacteria (0.5 to 2X10(6) bacteria per ml) for 2 h at 37 degrees C. At a bacteria/macrophage ratio of 1, only 34.8+/-7.0% of bacteria survived (compared to killing by non-loaded macrophages), while 74.4+/-9.3% survived at a ratio of 4. From these results, we conclude that loading macrophages with exogenous MPO could enhance their microbicidal activity, suggesting a potentially useful therapeutic application. [less ▲]

Detailed reference viewed: 159 (0 ULg)
See detailLes bactéries lactiques, une aide alimentaire.
Thonart, Philippe ULg; Roblain, D.

in Mellitus Magazine (1992), 3

Detailed reference viewed: 10 (3 ULg)
See detailBacteriochlorin a activated oxygen forms production: a ESR and a laser flash photolysis study
Hoebeke, Maryse ULg; Lindqvist, L.; van de Vorst, A.

Conference (1996)

Detailed reference viewed: 4 (1 ULg)